For our little co-op - renewable energy - a small wind turbine providing elecky in winter, coupled with solar panels for summer - would we maybe be able to light a small part of the house with it? Would it make a good investment, in a place like Britain? In Italy, Duino - where the Bora blows hard, cats go flying past, wind turbines over cooperative communities would make the communal experience very satisfying - even allowing for generation of enough wattage for a small band to play!
But hold on to your hat.
And the fiesta system. I would put together the fiesta system for all the communities strewn across the UK if I had the time and dedication. Maybe that is this elusive dream job. Do I want to be renowned for my creativity only, or actually do something more menial yet actually of practical use? Setting up the systems to allow for large spending - bringing people to sell their goods periodically - for maybe 2 different seasonal festivals for each town. Travellers would then become market people moving between communities following the fiestas to sell their produce or move it between different places and you'd have a low cost distributed commerce system - perhaps independant of any non-local, unethical or consumerist produce. Of course, there would also be music, and arts - and rituals! modern post pagan rituals would probably be the most used as it's the tradition in alternative britain.
And the fiestas themselves would be like festivals - a time to bring more people to their area and sell what they make or bring publicity or other benefits, although they would also be an expense: although I'm not against any form of charging outright - in the andean allyu this works because each place puts down the resources for it's own festival, but then expects each other area to offer their own resources when it's their turn - so you gain the rest of the year, but have to work hard when it's your turn. Larger scale fiestas might be a problem - some festivals will undoubtably be more popular. I don't know how this problem was balanced in the time of the Aymara kingdom - but I imagine the Andean Ayllu was always of a definite small size - a few families, and had systems for splitting when they grew too much, so no fiesta would have been beyond the means of a single or a couple of local Ayllus.